You used to see it anywhere business workers congregated: the BlackBerry. Some of them are still out there -- secure messaging devices that can be centrally managed; the heart of the business mobile fleet. But the day of the BlackBerry is over and something new is needed -- a mobile operating system that is built for work as well as personal use.

Microsoft's latest phone OS is trying to make a play for the enterprise high ground, with a mix of its Windows 10 Mobile platform, a new application development model and a suite of business-focused cloud services. But how well does it fit the needs of today's companies?

Enterprise license: Manage phones and deliver your own apps

To start with, there's one key feature that differentiates Windows 10 Mobile from other mobile operating systems: The ability to unlock a series of additional enterprise functions when connected to an Enterprise Mobility Management (EMM) suite. Microsoft recently made available an XML file which converts the standard version of Windows 10 Mobile into Windows 10 Mobile Enterprise when deployed onto a device. There's no need to install a new OS --just deliver the file, reboot and you're ready to go.

The app store model used by most mobile platforms makes it hard to deploy and manage a company's internal applications on mobile devices. If you're using an EMM solution, then you should be able to sideload internal apps -- either your own code or volume-licensed applications -- onto managed devices. Unlocking Windows 10 Mobile's Enterprise features allows you to install an unlimited number of self-signed applications on managed devices (as opposed to a limit of 20 on consumer devices).

Removing limits sounds good, but then there's the question of just how many corporately licensed apps you'll be installing on your users' mobile devices. In practice, users will likely need only one or two business apps, along with business email, all of which can be managed on consumer devices using any EMM that supports Windows 10 Mobile.